So, some pros and cons as someone who has published on both...
Drivethru: - keep higher % of earnings - no limitations on using your own IP - fewer limitations on distribution - smaller market looking exclusively for 5E content - must not use any content or trade dress held by WotC
DMsGuild: - keep lower % of earnings - unable to distribute in any other medium - giving up some exclusivity of your own IP - much larger market looking for 5E content - freely able to use a large portion of official 5E content and IP, including trade dress
Summary: - If you want it to look similar to official content or contain any official IP and cater to a very large market looking for 5E content, the bigger pool of customers can offset the earnings differential and you should use DMsGuild
If you want more control of your IP and distribution and can keep it all OGL and layout in your own style, you might as well keep the higher earnings and use Drivethru
EITHER can be effective as long as you're willing to market your products
Good luck!